Mechanical device



Aug. 9, 1949. H. E. OVERACKER MECHANICAL DEVI CE 2 Sheets-Sheet 1 Filed Jan. 17, 1946 FIG. 7

INVENTOR HORACE E. OVERACKER ATTORNEY 1949-v H. E. OVERACKER 2,478,307

MECHANICAL DEVICE Filed Jan. 1'7, 1946 2 Sheets-Sheet 2 ump 6 F c. s

- INVENTOR HORACE Ev OVERACKER ATTORNEY Patented Aug. 9, 1949 MECHANICAL. DEVICE Horace E. Overacker, San Francisco, Calif.,. as-

signor to the United States of America as represented by the Secretaryof War Application January 17,

1946, Serial No. 641,836

3 Claims. (Cl. 200-153) The invention. to be hereinafter described relates to an automatic motor driven sector sweep.

When radio messages. are known to be coming in within a considerable rad-i frequency range or band. but the approximate frequency is unknown, the entire. range must be scanned until the particular frequency is found and the set is then tuned to that. But, the message desired to be found often. occurs only at long intervals, infrequently and is of very short duration. Such would. be the case of enemy messages. In all such cases, manually operated scanningv is very unsatisfactory for many obvious reasons.

The main. objects of the present invention are to overcome the above and other objections and provide a highly eifieient, simple, compact and very readily constructed and assembled automatic sector sweep which, once started, will continue without attention as long as desired.

In order to more clearly disclose the construc- "on, operation and use of the invention, reference should be had to the accompanying drawings forming part of the present application.

Throughout the several figures of the drawings like reference characters in the different views- In the drawings Fig. I is a cross section through a dial shaft mounting and associated parts, showing thev invention;

Fig. 2 is a front elevation of the dial shaft, dial disc, hub and pointers, assembled;

Fig. 3 is a separate showing of the cam arms and their mountings;

Fig. 4 is a group illustration of one cam arm;

Fig. 5 is a like View of the other cam arm;

Fig. 6 is a group illustration of one pointer; and

Fig. 7 is a like view of the other pointer.

The usual dial shaft I is journaled in well known manner in the case or box or cabinet of the set. It may be either manually driven or motor driven. Preferably, it is motor driven and revoluble in either direction.

Freely revoluble on shaft I are two concentrically disposed sleeves, the inner sleeve 2 being of greater length than and extending appreciably beyond the outer sleeve 3 and the outer sleeve being freely revoluble on the inner sleeve. Freely revoluble relatively to said sleeves and mounted about the outer end of sleeve 3 is a dial hub 4 designate the: same. parts i.

carrying the usual disc or circular dial plate 5 which may be fractionally viewed in usual manner through the window or opening 6, the usual pointer or index I being provided.

Hub 6 is provided with an annular circumferential flange. 8, for a purpose to be later disclosed. Hub 4 is. anchored or locked to shaft I to rotate therewith in well known manner. The anchoring device shown comprises a block or collar 9 secured to the reduced outer end of I by a set screw or the likev I0. Pivoted in the collar to. swing radially outward therefrom is a short rod or bolt II whichv carries at its free end a pin I2 adapted to be seated in a hole in the hub 6. When in operative position, as shown in. Fig. 1, this anchoring device, compels the hub 4 and shaft I to rotate together. The dial disc 5 is fast to hub 4 and rotates with it and, consequently, with shaft I. Since flange 8 is integral Withhub 4., it has the same rotation as the dial plate 5.

Locked to and revoluble with the inner sleeve 2 is a switch actuating cam arm i3, extending radially outwardly from the sleeve. A preferred connection between the cam arm and sleeve is a tongue I4. adapted to fit into a cooperating notch or socket I5 in the sleeve 2. A simple and efiicient arrangement is to provide the arm I3 with a ring I 6 having an inside diameter equal to that part of the outside diameter of 2 over which the ring is to be slipped. Then, by aligning the tongue. I4 and notch I5, the ring or eye I6 be slipped over the reduced end thereby locking that cam arm to that inner sleeve 2 so that it will be compelled to. rotate therewith. In the same way, a second cam arm I! similar to the cam arm I 3 is. connected to the outer sleeve 3. The tongue iii of the ring or eye IQ of that cam arm I? slips into a notch or groove in a reduced part of the sleeve 3. A spacer 2| on the reduced part of 2, between cam arms I 3 and I I, maintains them in spaced relation, while the hub of a gear on shaft I, abutting the ends of sleeve 2 prevents arm I! slipping off.

A well known type of reversible motor, not shown, for driving or rotating the dial shaft may be used. According to the present invention, a toggle switch 22 of well known construction and arrangement may be used for such motor. It is so mounted that it will lie in the path of travel of arms l3 and I! as they are moved by their respective sleeves 2 and 3.

To effect movement of these cam arms, they must be connected to shaft I. This is done by connecting their sleeves to hub 4. For this purpose pointers 23 and 29 are provided. Pointer 23 is provided with a ring 24 and a tongue 25, a ring fitting over the reduced end of inner sleeve 2 while tongue 25 seats in a suitable notch in said sleeve 2. Ring 24 of pointer 23 is attached to sleeve 2 in a manner similar to that of ring l6 of cam l3 as shown ,in Fig. 3. In position, pointer 23 and ring 24 lie fiush against the rear face of hub Al. Pointer 23 may be securely locked to hub l by a hook 21 slidably mounted thereon and extending behind the flange 3 on the hub. It is only necessary to slip the hook radially along the pointer until it extends behind the flange and then tighten the clamping screw 28. Then, as dial shaft l and hub 4 are rotated, the pointer 23 and attached inner sleeve 2 will move and their movement will be the same. It will be remembered that cam arm l3 and pointer 23 are on the opposite ends of the inner sleeve 2. Consequently, as shaft l, hub 4 and pointer 23 swing, cam arm l3 must and will swing in the same direction and to the same extent.

Likewise, a second pointer 29, with ring 3!) and tongue 3| is similarly secured to a reduced outer end of the outer sleeve 3, the tongue seating in a suitable notch in said sleeve 3. Ring 38 of pointer 29 is attached to sleeve 3 in a manner similar to that of ring IQ of cam i! as shown in Fig. 3. In position, it underlies the ring of pointer 23. Accordingly, its pointer arm is deflected at 33 so that it, too, may lie flush with the dial plate. Cooperating with pointer 29 is another hook 34 and set screw 35 for anchoring the pointer in position. As in the case with pointer 23, looking pointer 29 to the hub 4 compels movement therewith and that, in turn, compels corresponding movement of sleeve 3 and cam arm ll.

From the above, it will be noticed that if pointers 23- and 29 are anchored to the hub in a predetermined angular relation such as 30 degrees apart, the cam arms l3 and 11 will, also, be disposed in the same angular relation of 30 degrees separation. Since the pointers are adjacent the dial disc, ferentially any desired reading distance on the radio dial such as from 50 me. to '70 me. It has been previously stated that the toggle switch 22 of a reversible motor may be disposed in the path of travel of the cam arms l3 and 11. Since the object of their engagement with the switch is to reverse the motor in order to reverse the drive of the dial shaft they are of course opposite'ly deflected so that, in respective engagement with the switch they will swing it oppositely. So, if the two pointers are set, respectively, at 50 and '70 inc. and rotation of the shaft is such, to start with, as to swing from 50 to '70, one of the cam arms will engage and operate toggle switch 22 as the dial reaches the '70 reading. That will reverse the motor and the dial will swing toward 50. As it reaches the reading of 50 the other cam arm comes into play and again reverses the motor and direction of drive. In this way the same sector, or frequency range may be automatically scanned or swept as frequently and continuously as desired.

Any suitable gear train may be used between the motor and tuning shaft as will be well understood. Since the reversible motor and such gear they may be spaced circumtrains are amply well known by all skilled in the art to which this invention relates, it would add nothing to the understanding or clearness of this invention to further describe or illustrate them but, on the other hand, would unnecessarily increase the size and bulk of the record with no offsetting advantages.

It will be well understood, also, that such motor drive or operation will in no way interfere with hand operation. The combination of both operations is not new to those skilled in the art. With such combination operation, rotation of the dial shaft by the hand operated drive beyond the point of contact between toggle switch 22 and one of the cam arms I"! or 23 would be indicated by the click of the toggle switch. Both the manual operation mechanism above and the manual and motor drive in combination are known to those skilled in the art. No claim to such is made in this application. They are no part of this invention. Accordingly, neither of them will be further described or illustrated in this application as to do so would simply needlessly encumber the record with no practical gain or offsetting advantage. The true invention would be more beclouded than clarified by such.

It is thought that the construction, operation and use of the invention will be clear from the preceding detailed description.

Many changes may be made on the construction, arrangement and disposition of various parts of the invention within the scope of the appended claims, without departing from the field of the invention and it is meant to include all such within this application wherein only one preferred form of the invention has been illustrated purely by way of example and with no thought of, in any degree, limiting the invention thereby.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. In combination, a radio dial shaft, a switch in the proximity thereof, a sleeve freely revoluble on said shaft, means carried by said sleeve engaging and actuating said switch as said sleeve is moved in one direction, a second sleeve freely revoluble on the first sleeve, means carried by said second sleeve engaging and actuating said switch during movement of said second sleeve in a direction opposite to that of the movement of the first sleeve and means for securing said sleeves to said shaft in angularly spaced relation about said shaft to travel with said shaft.

2. In combination, a radio dial shaft, a switch in the proximity thereof, a sleeve freely revoluble on said shaft, means carried by said sleeve engaging and actuating said switch as said sleeve is moved in one direction, a second sleeve freely revoluble on the first sleeve, means carried by said second sleeve engaging and actuating said switch during movement of said second sleeve in a direction opposite to that of the movement of the first sleeve, means for selectively angularly spacing said switch actuating means relatively to each other about the aforesaid shaft and means for separately securing each of said actuating means in such selected position whereby movement of said shaft compels movement of said switch actuating means therewith in such selected predetermined spaced relation.

3. In combination, a rotatable shaft, a radio dial secured to said shaft, a toggle switch having an operating lever, the operating lever being disposed in proximity to said shaft, a first sleeve freely revolvable on said shaft, a cam arm secured to said shaft and extending radially therefrom to engage said toggle whereby said switch is actuated when said sleeve is moved in one direction, a second sleeve freely revolvable on said first sleeve, a cam arm secured to said second sleeve and extending radially therefrom to engage said operating lever whereby said switch is actuated reversely during movement of said second sleeve in a direction opposite to that of the movement of said first sleeve, a first pointer connected to said first sleeve, said first pointer being adjacent to said dial, a second pointer secured to said second sleeve, said second pointer being adjacent to said dial, and means for separately clamping said first and second pointers to said dial at selected and angularly spaced positions thereon to cause said first and second sleeves to travel with said dial whereby said cams are maintained in a corresponding angular relation and said switch is actuated in accordance with said angular relation.

HORACE E. OVERACKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 748,638 McQuown Jan. 5, 1904 1,876,476 Tanner Sept. 6, 1932 1,947,332 Christen Feb. 13, 1934 2,370,701 Woodbury Mar. 6, 1945 FOREIGN PATENTS Number Country Date 839,812 France Jan. 7, 1939 

